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The molecular mechanism behind pain in degenerative disc disease (DDD) and chronic low back pain (LBP) patients is largely unknown. This present study examines the association of LBP and disability to mediators of the inflammatory cascade, as indexed by mRNA gene expression of pro-inflammatory cytokine markers in the intervertebral disc (IVD). Biopsies of the annulus fibrosus (AF) and the nucleus pulposes (NP) from patients with DDD undergoing 1–2 level fusion surgery at L4/L5 or L5/S1 were obtained from total of 34 patients [9 M, 25 F] with average age of 53 [32–63]. The mRNA expression of TNF-α, IL-1β, and IL-6 in the AF and NP was analyzed using quantitative real-time polymerase chain reaction (RT-qPCR), and the expression level of these markers was correlated to the visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores (0–100) for pain and disability. We report a statistically significant positive correlation between pain intensity (VAS score) and the expression of TNF-α in both the AF (r = 0.54, p = 0.001) and NP (r = 0.40, p = 0.02), similarly with IL-1β in AF (r = 0.37, p = 0.02) and IL-6 in NP (r = 0.40, p = 0.02). In addition, we found significant positive correlation observed between disability score (ODI) and expression of IL-6 in both AF (r = 0.36, p = 0.03) and NP (r = 0.41, p = 0.01). We conclude that the intensity of LBP and disability is associated with the level of inflammation in the disc.

The molecular mechanism behind pain in degenerative disc disease (DDD) and chronic low back pain (LBP) patients is largely unknown. This present study examines the association of LBP and disability to mediators of the inflammatory cascade, as indexed by mRNA gene expression of pro-inflammatory cytokine markers in the intervertebral disc (IVD).Biopsies of the annulus fibrosus (AF) and the nucleus pulposes (NP) from patients with DDD undergoing 1-2 level fusion surgery at L4/L5 or L5/S1 were obtained from total of 34 patients [9 M, 25 F] with average age of 53 [32-63]. The mRNA expression of TNF-α, IL-1β, and IL-6 in the AF and NP was analyzed using quantitative real-time polymerase chain reaction (RT-qPCR), and the expression level of these markers was correlated to the visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores (0-100) for pain and disability.We report a statistically significant positive correlation between pain intensity (VAS score) and the expression of TNF-α in both the AF (r = 0.54, p = 0.001) and NP (r = 0.40, p = 0.02), similarly with IL-1β in AF (r = 0.37, p = 0.02) and IL-6 in NP (r = 0.40, p = 0.02). In addition, we found significant positive correlation observed between disability score (ODI) and expression of IL-6 in both AF (r = 0.36, p = 0.03) and NP (r = 0.41, p = 0.01).We conclude that the intensity of LBP and disability is associated with the level of inflammation in the disc.

EI; We report the first observation of coherent pion production induced by a heavy ion charge exchange reaction. The ($^12$C,$^12$N) reaction [D. Bachelier et al., Phys. Lett. B 172 (1986) 23; M. Roy-Stephan et al., Nucl. Phys. A 488 (1988) 178] at 1.1 GeV/nucleon has been used to shine negative (off-shell) pions on nuclei and observe (on-shell) pions, leaving the target nucleus in its ground state. The experiment was performed at the Laboratoire National Saturne with the SPES4$_\pi$ setup [Laurent Farhi PHD thesis IPNO-T97-12, Universite d'Orsay, 1997; Rasmus Dahl Ph.D., Niels Bohr Institutet, Copenhagen (1999)].

The exclusive 2H( 3He, t)2p reaction has been studied at 2 GeV for energy transfers up to 500 MeV and triton angles up to 3.4°. The protons were measured in the large acceptance magnetic detector DIOGENE, in coincidence with the forward tritons detected in a dedicated magnetic arm. The energy transfer spectra extend well above the pion threshold. However, in the region of Δ excitation, the yield is less than 10% of the inclusive 2H( 3He, t) cross-section, which indicates the small contribution of the ΔN ↦ NN process. The angular distributions of the two protons in their center of mass have been analysed as a function of energy transfer and triton angle and a Legendre polynomial decomposition has been achieved. These data have been compared to a model based on a coupled-channel approach for describing the NN and NΔ systems.

The inclusive 2(3He,t) reaction has been studied at 2 GeV for energy transfers up to 500 MeV and scattering angles from 0.250 up to 40. Data are well reproduced by a model based on a coupled-channel approach for describing the NN and NΔ systems. The effect of final state interaction is important in the low energy part of the spectra. In the delta region, the cross-section is very sensitive to the effects of Δ-N interaction and ΔN → NN process. The latter has also a large influence well below the pion threshold. The calculation underestimates the experimental cross-section between the quasi-elastic and the delta peaks; this is possibly due to projectile excitation or purely mesonic exchange currents.

Experimental data on the nuclear spin-isospin response in the quasifree region, measured with the charge-exchange reaction (d\ensuremath{\rightarrow},2p${[}^{1}$${\mathit{S}}_{0}$]) at Laboratoire National Saturne, are presented. The use of a tensor-polarized beam enables us to separate the tensor analyzing powers ${\mathit{T}}_{20}$ and ${\mathit{T}}_{22}$. The present publication is intended to serve as a compilation of the complete set of quasifree data with the (d\ensuremath{\rightarrow}${,}^{2}$He) reaction at 1.6 GeV bombarding energy. Data for $^{12}\mathrm{C}$ are compared to calculated cross sections and tensor-analyzing powers. The cross section in the high-energy end of the quasielastic peak is underestimated, whereas the polarization observables are reasonably well reproduced. The distortion effects are, however, found to be large, suggesting that the (d\ensuremath{\rightarrow}${,}^{2}$He) reaction is not sensitive to spin correlations in the continuum.

Data are presented on the 12 C ( 3 He , t π + ) reaction at 2 GeV bombarding energy. In coincidence with forward scattered tritons, pions are momentum-analysed in a large acceptance detector. For events where the target is left in its g.s. or low-lying states, the angular correlation between the momentum transfer vector and the momentum of the pion is sharply peaked at small relative angles.

Data for the (3He, t) reaction at 900 MeV and 2 GeV on the targets 26Mg, 40Ca, 48Ca, 54Fe, 90Zr and 208Pb are presented. A multipole decomposition for the data at 900 MeV has been made and the different distributions have been analysed. From the L = 0 cross section the Gamow-Teller strength distributions are extracted and compared with (p, n) data. The L = 1 and 2 distributions are analysed in a schematic model which describes the general systematics fairly well. The spectra at 2 GeV and Θ = 4° show for all targets a well-developed quasi-elastic peak. The A-dependence of the cross section is analysed in a simple model.

Zero-degree cross sections have been measured for the {sup 11}B({ital p},{ital n}){sup 11}C reaction at bombarding energies of {ital E}{sub {ital p}}=160, 200, 494, 644, and 795 MeV. In addition, spectra have been obtained at laboratory scattering angles of 3{degree} and 5{degree} at 494 MeV, and the transverse spin-flip probability at zero degrees has been measured for {ital E}{sub {ital p}}=160 MeV. These data are used to obtain estimates of the Gamow-Teller transition strength to final states in {sup 11}C up to an excitation energy of {ital E}{sub {ital x}}{approx equal}14 MeV. The uncertainty (1 standard deviation) in the extracted transition strengths is estimated to be in the range (2--8)%. Measured cross sections for the first four excited states in {sup 11}C have been compared to distorted-wave impulse approximation calculations. In this comparison, no evidence is found in the cross-section data for certain effects associated with knock-on exchange and noncentral interactions.

Differential-cross-section distributions for the {sup 7}Li({ital p},{ital n}){sup 7}Be(g.s.+0.43-MeV) reaction have been measured for {ital E}{sub {ital p}}=80, 120, 160, 200, 494, 644, and 795 MeV. These distributions have been integrated and normalized to independent values for the total cross section obtained from parametrizations of {sup 7}Li({ital p},{ital n}) activation measurements. Zero-degree cross sections obtained from this normalization are reported.

Differential cross section angular distributions for the $^{6,7}\mathrm{Li}$(p,n${)}^{6,7}$Be reactions have been measured at energies between 60 and 200 MeV. The experimental angular distributions are analyzed using a microscopic distorted wave impulse approximation. The results of self-consistent microscopic distorted wave calculations based on a complete set of weak and electromagnetic data for the mass 6 and 7 systems are also presented. Total observed Gamow-Teller strength up to about 40 MeV excitation energy is reported. Energy dependence of the \ensuremath{\sigma}\ensuremath{\tau} and \ensuremath{\tau} effective interaction terms are presented up to 200 MeV. The measured (p,n) cross sections for the $^{7}\mathrm{Be}$ (g.s.) and $^{7}\mathrm{Be}$ (0.43 MeV) transitions are used to obtain the branching ratio of the $^{7}\mathrm{Be}$ (g.s.) decay to the g.s. and 0.478 MeV states in $^{7}\mathrm{Li}$. Zero degree polarization transfer (${\mathit{D}}_{\mathit{N}\mathit{N}}$) data at ${\mathit{E}}_{\mathit{p}}$=80, 120, 160, and 200 MeV are reported for the $^{6}\mathrm{Li}$(p,n${)}^{6}$Be (g.s.) and for the $^{7}\mathrm{Li}$(p,n${)}^{7}$Be (g.s.+0.43 MeV) reactions. Energy dependence of total and zero degree differential cross section for the $^{7}\mathrm{Li}$(p,n${)}^{7}$Be (g.s.+0.43 MeV) transitions are reported. Finally a comparison is presented for the (n,p), (p,p'), and (p,n) reaction in $^{6}\mathrm{Li}$ populating isospin triplets.

We discuss the spin-isospin response in 3 regions. The Gamow-Teller strength distribution is still not understood. New data from ( n , p ) reactions question the conjecture that part of the missing strength was to be found in the high energy tail region. In the quasielastic region rather different sets of data suggest that the attraction in the spin longitudinal channel is gone. In the Δ-region the existing data are consistent with an attractive Δ-hole interaction in the spin longitudinal channel.

EI SEP PHASE ACC; The paper describes the spectrometric system “SPES4–$\pi$” used at the National Laboratory Saturne (CE Saclay, France) for the exclusive study of the baryon resonance excitation in inelastic α and d scattering on the proton, as well as coherent pion production in charge exchange reactions. The system consists of the magnetic spectrometer SPES4 and two wide-aperture position-sensitive detector arrays, equipped with wire chambers and scintillator hodoscopes, installed around a large-gap C-shape dipole magnet.

We shall discuss the nuclear spin response as measured in charge exchange reactions at intermediate energies. We shall especially be interested in the spin-longitudinal part of the response. This is where the largest effects from particle-hole correlations at larger momentum transfer are expected. The attraction in the spin-isospin channel as seen in NN scattering and dominantly coming from one pion exchange would give very dramatic effects inside a nucleus. That is, if we just took the particle-hole interaction equal to the free NN-interaction in this \(\overrightarrow \sigma \overrightarrow q\) spin-longitudinalchannel. Similar dramatic effects could be expected in the Δ-region. The question is then, what are the effective particle-hole or Δ-hole interactions at finite momentum transfers.

The reaction 42 Ca(p,n) 42 Sc at E p = 160 MeV is used to measure the Gamow-Teller (GT) strength function. Normalization of the dominant peak in the (p,n) spectrum to B (GT) determined from the analogous transition in the beta decay of 42 Ti renders the strength function absolute, and the total measured stregth is about half of the minimum value required for a T = 1 nucleus. Shell model calculations are presented which reproduce the shape of the strength function, but overpredict the absolute measured strength by about a factor of two. Evidently the missing strength has been moved out of the region of nucleon particle-hole excitations, and quenching, due possibly to Δ 33 coupling, is indicated. Symmetry implications of an observed strong suppression of the T > component of the GT strength are discussed.

Data for the Δ excitation by the (3He,t) reaction at 2.0 GeV on various nuclei are presented together with results on 12C at 1.5 and 2.3 GeV. The Δ peak position and width are found to be target mass independent. Comparison with the p(3He,t) Δ++ reaction, however, shows a shift of the position in energy of the Δ peak. Implications of these results are discussed.

The 58Ni(p,n)58Cu reaction has been studied at 120 MeV and 160 MeV incident energies. States in 58Cu with Gamow-Teller (GT) strength, identified by its L=0 angular distribution, have been observed up to an excitation energy of ∼14 MeV. The excitation of a broad resonance at ∼9 MeV excitation is identified as the main T=1 component of the GT strength in 58Cu. Comparison with shell model calculations using an fp model space indicates that the GT strength cannot be clearly resolved in terms of its T=0, 1 and 2 components. We find that the sum of the experimentally observed GT strength is ∼55% of the theoretically predicted value. Comparison is made with published M1 results from the 58Ni(e,e′) reaction.

Data are presented for the (/sup 3/He, t) reaction at energies of 600 MeV, 1.2 GeV, and 2 GeV on targets /sup nat/C, /sup 54/Fe, and /sup 89/Y. The low--excitation-energy regions of the spectra are dominated by isospin-spin excitations. Cross-section calculations in distorted-wave impulse approximation with parameters from NN data account reasonably well for the data. At 2-GeV bombarding energy a strong excitation of the ..delta.. resonance is observed for all targets.

Excitation of the Δ resonance has been observed for the first time in a heavy ion reaction. The strength of the Δ signal depends on the projectile nuclear structure. In the same incident energy range, about 900 MeV per nucleon, we observe — a strong Δ excitation in 27 Al( 20 Ne, 20 F) and 27 Al( 20 Ne, 20 Na), — a weak Δ in 12 C( 14 N, 14 C) and — nearly no Δ excitation in ( 12 C, 12 B) and ( 12 C, 12 N) whatever the target is among a sample of nuclei from 12 C to 89 Y.

Neutron spectra from $^{37}\mathrm{Cl}$($p$,$n$)$^{37}\mathrm{Ar}$ at ${E}_{p}=120$ MeV are measured in the angular range 0\ifmmode^\circ\else\textdegree\fi{}-30\ifmmode^\circ\else\textdegree\fi{}. Neutron groups characterized with $L=0$ transfer are obtained up to approximately 12-MeV excitation energy in $^{37}\mathrm{Ar}$. From the observed 0\ifmmode^\circ\else\textdegree\fi{} cross section the Gamow-Teller strengths for $^{37}\mathrm{Cl}$\ensuremath{\rightarrow}$^{37}\mathrm{Ar}$ transitions are obtained which are directly related to neutrino absorption by $^{37}\mathrm{Cl}$. The cross section for $^{8}\mathrm{B}$ solar neutrinos incident on $^{37}\mathrm{Cl}$ is reported.

Data on the Δ-isobar production in the pp → n Δ ++ reaction have been analyzed, the parameter Λ of the π NN, π N Δ vertex form factors is found to be Λ = 0.63 GeV. The reaction 3 He + p → 3 H + Δ ++ is analyzed using the pp-nΔ ++ amplitude.

For protons and heavier ions with energies in the MeV range we have studied the production of characteristic X-rays from elements with Z ≳13 using a semiconductor X-ray spectrometer. Various competing background processes have been identified. Theoretical estimates of the background radiation due to bremsstrahlung from secondary electrons and due to proton bremsstrahlung have been evaluated, and on this basis we have calculated lower limits for the sensitivity obtainable for the concentration of the trace element, ranging down to values of 10 −6 −10 −7 . Different projectiles and incident energies have been compared, and it is shown that this method of X-ray production is about 3 orders of magnitude cleaner than can be obtained by electron bombardment.

Data on (p,n) reactions at 120 and 160MeV have been used to study the excitation of spin-isospin multipole vibrations in 54, 56Fe and 58, 60Ni. In particular, transitions characterized by L = 0 transfer are identified as spin-isospin transitions (excitation of Gamow-Teller states) or as isospin transitions (excitation of isobaric analog states). An effort is made to estimate Gamow-Teller strength, B(GT), at excitation energies between 20–40 MeV. A comparison between GT and M1 strengths is presented for 58, 60Ni. Shell-model calculations for total strengths, Σ B(GT), are compared with the observed results.

High-spin states have been located in 153Sm by means of the (α, 3He) reaction with 40 MeV α-particles. The scattered particles were momentum-analysed in a QMG 2 magnetic spectrometer and recorded in a position-sensitive detector. Several high-spin states were observed below 2 MeV of excitation. Strongly populated levels at 698, 1118 and 1708 keV can most likely be interpreted as 13 2 + states. The deduced nuclear structure factors and the energy location of these levels are compared with the neighbouring isotope 151Sm and with a particle-rotor-model calculation of the i 13 2 spectra.

We have succeeded in measuring at 0\ifmmode^\circ\else\textdegree\fi{} and small angles the energy spectra for the (d,2p${[\mathrm{}}^{1}$${S}_{0}$]) reaction (with the two protons in the singlet S state) at 650 MeV and 2 GeV. It is demonstrated that the reaction is a one-step process that can be used to study isospin-spin excitations. The \ensuremath{\Delta} excitation is very clearly observed. A shift down in energy of the \ensuremath{\Delta} peak from the proton to the $^{12}\mathrm{C}$ target is observed. The experiments are performed with a tensor polarized beam and the tensor analyzing power for the p(${d}_{\mathrm{pol}}$,${\mathrm{}}^{2}$He)n reaction at 2 GeV is given.

The (p, n) reactions on 19 F and 39 K targets have been studied at 120 MeV and 160 MeV using the Indiana University Cyclotron time-of-flight facility. States up to 12 MeV excitation energy have been observed and angular distributions for these neutron groups are presented. The ground-state mirror transitions have accurately measured ft values. This information is used to normalize the zero-degree energy spectra to a scale of Gamow-Teller (GT) transition probability to obtain GT strenghts to excited states. The experimental sum GT strengths are smaller than the sum-rule-limit values showing strong evidence for GT quenching.

Δ-excitations as studied by charge-exchange reactions are discussed. Spectra from (3He, t), (d, 2p[1S0]) and charge-exchange reactions with heavy ions like (12C, 12N) and (16O, 16N) are shown. In all these reactions the Δ-excitation is seen as a prominent part of the spectra. In all the reactions a shift is observed between the energy of the Δ-peak in nuclei (A ⩾ 12) and on the proton. Also discussed is the quasi-elastic peak seen in the (3He, t) and (d, 2p[1S0]) reactions. We follow the peak from q ∼ 1.3 to 2.5 fm−1 and see a shift of the centroid energy relative to the free nucleon as a function of q.

The evidence for a useful proportionality relationship between 0° (p, n) cross sections and the corresponding Gamow-Teller and Fermi beta-decay transition strengths is examined in detail. A simple parameterization for small momentum transfer L = 0 transitions is developed and used in the analysis of (p, n) data in the bombarding energy range 120–200 MeV. The parameterization describes the (p, n) differential cross section in terms of momentum transfer, energy loss, mass number, and bombarding energy and provides a straightforward way of extrapolating to zero momentum transfer. It is found that a single proportionality constant can serve to relate all Gamow-Teller transitions originating from the same target nucleus. The target dependence of this proportionality constant, however, is found to be unpredictable at the 20%–50% level, even within isotopic chains. Such large variations cannot be easily explained in the context of the standard single-step direct-reaction distorted-waves impulse approximation model.

Neutron time-of-flight measurements have been performed on the 81 Br(p,n) 81 Kr reaction at E p = 190 and 200 MeV. Gamow-Teller transition strengths have been deduced for final 81 Kr states accessible through solar neutrino capture on 81 Br. For the standard solar model, 81 Br is most sensitive to 8 B neutrinos, not — as previously believed — 7 Be neutrinos.

Data are presented for the p(3He,t)Δ++ reaction at 2.0, 2.3 and 1.5 GeV. The reaction specifically excites the Δ++ with very little yield outside the resonance. The data are analysed as one pion exchange and the hadronic form factor for the 3He−1 system is extracted and compared with the magnetic form factor from electron scattering.

The evaporation residue cross section has been measured for the 16 O + 27 Al system at 50, 60, 65, 70, 75 and 80 MeV bombarding energy using the time-of-flight technique. The model of Glas and Mosel is used in the analysis of the fusion cross-section data. The relative abundance of evaporation residues is compared with statistical model calculations.

Energy systematics of the giant Gamow-Teller resonance and a charge-exchange resonance excited by a L = 1, S = 1 interaction are presented. Plots of the energy separation between each resonance and the IAS versus (N − Z) A can be represented approximately by linear functions.

Angular distributions have been measured for the ( 6 Li, 6 He) reaction on the targets 19 F, 27 Al [ E( 6 Li ) = 34 MeV ] and 58, 60, 64 Ni [E( 6 Li ) = 36 MeV ]. Upper limits are given for the cross sections for the 40 Ca( 6 Li, 6 He) 40 Sc and 88 Sr( 6 Li, 6 He) 88 Y reactions at E( 6 Li ) = 38 MeV . The spectra were obtained with 60 cm long position sensitive counters in a magnetic spectrograph with a resolution around 50 keV. A strong Q -value dependence on the cross section is observed. The data are analyzed using DWBA with a microscopic description of the reaction. The σσττ two-nucleon force strength extracted from the analysis shows variations that indicate that two-step processes could be important.

The /sup 40/Ca(p,n) reaction at E/sub p/ = 159.3 MeV excites a state at E/sub x/ = 2.7 +- 0.1 MeV in /sup 40/Sc. The energy dependence and differential cross section angular distribution for this reaction indicate that this state is the T/sub z/ = -1 analog of a known 1/sup +/ state at E/sub x/ = 10.32 MeV in /sup 40/Ca. We find that the Gamow-Teller strength for this 0/sup +/..-->..1/sup +/ (p,n) transition is B(GT) = 0.21 +- 0.04. Comparison of B(GT) to B(M1)up-arrow for the analogous M1 transition in /sup 40/Ca indicates a substantial orbital-current contribution to the M1 strength. The /sup 40/Ca(p,n) reaction also strongly excites a 2/sup -/ state at E/sub x/ = 0.77 MeV in /sup 40/Sc. Good agreement is found between properly normalized distorted-wave impulse approximation calculations and the measured differential cross sections for this transition at 159.3 MeV.

The (p, n) reactions on several targets from 40Ca to 208Pb have been studied at 200 MeV using the Indiana University Cyclotron time-of-flight facilities. In addition to giant Gamow-Teller (GT) resonances that dominate the zero degree spectra, other broad resonance structures appear at angles larger than zero degrees which are interpreted as spin-isospin multipole vibrations. GT strength and energy systematics as well as dipole spin strength and energy systematics are discussed.

Angular distributions for the ground-state (..delta..J/sup ..pi../ = 1/sup +/) and 0.96-MeV (..delta..J/sup ..pi../ = 2/sup +/) transitions in the /sup 12/C( p,n)/sup 12/N reaction have been measured at incident energies of 120, 160, and 200 MeV. The measured values of the differential cross section align themselves into smooth curves independent of incident energy when converted into plane-wave cross section values and plotted versus momentum transfer. This information supports the hypothesis that the spin-isospin term of the effective interaction is almost energy independent in this energy region. Microscopic distorted-wave impulse approximation calculations are presented.

A formulation of the (6Li, 6He) spin-isospin-flip scattering problem is presented. The method is applicable to quasielastic collisions between6Li described in pureLS coupling scheme and any target nucleus which can be described in a shell model or an adiabatic deformed-nucleus model picture. The effective interaction responsible for the (6Li, 6He) reaction involves an integration of the (σ1 · σ2) (ρ1 · ρ2) compo nent of the central part and the (τ1· τ2) tensor part of the nucleon-nucleon interaction over the internal wave function of the projectile. The 48Ca(6Li,6He)48Sc reaction populating the ( πf 7 2 νf 7 2 −1 ) multiplet in 48Sc is analysed. It that the tensor force makes some contribution to the transitions to high spin states.

In coincidence with tritons from the $^{208}\mathrm{Pb}$ ($^{3}\mathrm{He}$, $t$)$^{208}\mathrm{Bi}$ reaction proton spectra corresponding to decay into definite final states in $^{207}\mathrm{Pb}$ have been measured. The coincidence yield is described as exclusively coming from the decay of two resonances, the isobaric analog state (IAS) and the Gamow-Teller (GT) resonance. An analysis in terms of a formation cross section times a branching ratio gives a good description for the IAS and for the shape of the GT resonance. The yield from the GT resonance is, however, an order of magnitude larger than calculated.

Spin structure and cross section data for Δ production in the (n, p-like reaction (d, 2p[1S0]) on p, d and 12C targets are presented. At laboratory kinetic energies 2 GeV and 1.6 GeV, and forward scattering angles, we find dominance of spin transverse over spin longitudinal cross section for free Δ production. On the nucleus 12C we find significant enhancement of the transverse dominance, and a large downwards shift in the peak position of the laboratory energy transfer associated with the production of the Δ.

The 54 Fe( 3 He, t) 54 Co reaction has been studied at 70 MeV with an energy resolution around 70 keV (FWHM). The triton spectra are characterized by sharp peaks up to 10 MeV excitation energy superimposed on a continuum. Most of the sharp peaks have a forward-peaked angular distribution and 38 peaks or groups of peaks are found to have an angular distribution corresponding to an angular momentum transfer of 2. Model considerations lead to the conclusion that most of these states are 1 + states. A shell-model calculation with parameters that account for the Gamow-Teller strength distribution in 48 Ca- 48 Sc divides the β-strength in 54 Co in a ratio 5.7:6.8:1.3 for the T = 0, 1 and 2 states. A comparison is made with the 1 + spectrum in 54 Mn ( T = 2 states) and a tentative assignment of T = 2 states in 54 Co is reached. The cross section has been calculated for the 0 + , 1 + and 3 + states in 54 Co assuming a pure ( π f 7 2 −1 ν f 7 2 −1 ) configuration finite-range DWBA is used and the conclusions are that the ( 3 He, α, t) and ( 3 He, d, t) processes give significant contributions to the cross sections.

Angular correlations have been measured between light particles emitted in compound nucleus decay for different nuclei formed in heavy ion reactions. The reactions used were 16 O+ 27 Al at E l ab = 50 and 60 MeV, 16 O+ nat Ca and 16 O+ 58 Ni at 70 MeV. The αα, αp and pp correlations were measured in a plane perpendicular to the beam axis as a function of the relative azimuthal angle. The anisotropies wre around 5:1, 2:1 and 1.2:1 for the αα, αp and pp correlations respectively. Detailed calculations of the αα correlations in the geometry show that the correlation is sensitive to the angular momentum in the entrance channel. The yield for Δo = 180 primarily comes from the high angular momenta whereas the yield at Δo = 90° has contributions from all the angular momenta.

The 48Ca(3He, t)48Sc reaction has been studied at E3He = 66 MeV and 70 MeV. Angular distributions are given from θ = 8° to 35°. The 0+–7+ multiplet in 48Sc is strongly excited at these energies and the spectra are further characterized by some broad structures on a continuous background. Broad peaks at Eex = 7.8, 10.6 and 13.3 MeV have an angular distribution similar to the low-lying 1+ state. The broad peaks are interpreted as envelopes of groups of 1+ states carrying a significant part of the Gamow-Teller strength. The strength distribution is consistent with a shell-model calculation. The reaction mechanism has been examined at 66 MeV. The cross section is calculated for the 0+–7+ multiplet in 48Sc as a coherent sum of one-step and two-step processes. The two-step contribution is calculated in a full finite-range 2nd-order DWBA. The result is similar contributions from (3He, α, t) and (3He, d, t). The calculations account reasonably well for the data with the exception of the transition to 0+, IAS.

Total (p, n) cross sections to isobaric analogues of 0 + ground states are determined from the yield of γ-rays, de-exciting the IAS. Excitation functions are measured for targets 48 Ca, 50 Ti, 52 Cr and 58 Ni from threshold to 6.4, 4.0, 3.3 and 2.2 MeV above. The measured cross sections are compared with calculated cross sections for compound nuclear and direct reaction mechanisms. The decay scheme of the analogue state at 6.68 MeV in 48 Sc is established. Measured inelastic and elastic scattering of protons on 48 Ca at 8 to 10.2 MeV show correlations with the neutron channel leading to the analogue state.

The (3He, t) charge-exchange reaction leading to the ground-state isobaric analog states (IAS) of 152, 154, 156, 158, 160Gd, 160,162Dy, 162,164,166,168,170Er, 170, 172, 174, 176Yb and 176, 178, 180Hf has been studied at θL = 0° and E( 3 He) = 60.5 MeV . The reaction 28Si(3He, t)28P was used for energy calibration. The centroid energies of most IAS were determined to ±6 keV. Coulomb displacement energies have been extracted from the measured Q-values. They display the influence of non-spherical nuclear shapes which increase the rms radii and lower the Coulomb displacement energies. The dependence on both quadrupole and hexadecapole deformations is apparent with deformation parameters in good agreement with results from other measurements. The total widths Γ of the IAS are in the range 30 to 110 keV. They increase more strongly with neutron excess than is known for the IAS of the Sn and Te isotopes. The width of the IAS of 176Yb is anomalously low. The zero-degree (3He, t) cross sections are in the range 5 to 20 μb/sr. They generally increase with neutron excess except for the sequence of Yb isotopes. No systematic dependence on (N − Z) appears to exist. Excitation energies and zero-degree cross sections for the reactions 28Si(3He, t)28P, 16O(3He,t)16F and 12C(3He,t)12N are reported.

Results on the Δ excitation by heavy ion charge exchange are presented. 900 MeV per nucleon 12C, 16O, 20Ne and 1100 MeV per nucleon 12C have been used. The Δ excitation strength depends on the projectile — ejectile nature and on the incident energy. The role of the target mass is also discussed. The peak for the Δ in nuclei is energy shifted from the free Δ peak.

The (3He, t) reaction has been studied at intermediate energies, 600 MeV–2.3 GeV. The reaction is a single-step direct reaction, and the angular distributions are well described by DWIA calculations. At these energies the σρ component of the interaction dominates. The ratio of the isovector strengths ¦J σρ / ρ ¦ derived from the data on 13C appears to remain roughly constant in the energy range 300–700 MeV per nucleon. The triton spectra exhibit a prominent quasi-free peak. The data at momentum transfers q ⪢ 1.7 fm−1 show a shift of the peak towards smaller energy loss than observed in (e, e') experiments at corresponding four-momentum transfers. The shift becomes progressively larger with increasing q and is about 45 MeV at q = 2.5 fm−1. The shift may be caused by particle-hole correlations in the spin-longitudinal channel.